But an unanticipated difficulty in bulk production of the live attenuated virus
vaccine has slowed its progress.
This live attenuated virus
is given orally to mimic the transmission of the disease.
The risk for congenital varicella syndrome after natural infection with wild varicella zoster virus is 1%-2%; because the virulence of the attenuated virus
used in the vaccine is less than that of the wild-type virus, the risk to the fetus, if any, should be lower (1).
Since 1961, the preferred schedule has included four doses of the live attenuated virus
or the oral vaccine.
Ig administration can transiently impair the efficacy of live attenuated virus
vaccines, such as measles, mumps and rubella.
2016-2527) Pediatrics found that children between the ages of two and 17 who were vaccinated using nasal sprays with the live attenuated virus
were two and a half times more likely to fall sick than children who got a shot.
The danger of current attenuated virus
vaccines is that they might exchange dangerous genetic material with garden variety influenza viruses of the sort that strike annually, potentially rendering a lethal but very hard to transmit influenza virus, such as H5, easily transmissible among humans.
However, in contrast to other vaccines, YF vaccine is prepared with live attenuated virus
, and probably for other vaccines prepared in the same way we need to consider this possibility," wrote Dr.
Pregnant women are not advised to use the nasal spray form of the seasonal or pandemic H1N1 vaccines (Flumist), as both forms of this vaccine contain live attenuated virus
TABLE 1 LAIV vs TIV: How the 2 compare LAIV Route of administration Intranasal spray Type of vaccine Live attenuated virus
Approved age 2-49 years Interval between 2 4 weeks doses recommended for children 6 months to 8 years who are receiving influenza vaccine for the first time Use with other live virus Simultaneously or vaccines separated by 4 weeks Use with influenza Wait 48 hours after last antiviral medication antiviral dose to administer LAIV; wait 2 weeks after LAIV to administer antivirals Contraindications Chronic illness and precautions Chronic aspirin therapy History of Guillain-Barre syndrome Pregnancy Caregiver to severely immune-suppressed individual TIV Route of administration Intramuscular injection Type of vaccine Killed virus Approved age ?
With a live attenuated virus
, you have to err on the side of safety," says immunologist David H.
Because it is a live attenuated virus
- in other words, a weakened version of the polio virus - it can cause polio in people who have significantly compromised immune systems.
West Point, Pennsylvania]), a live attenuated virus
vaccine for preventing chickenpox, recently has been licensed for children aged [greater than or equal to]12 months.
In early clinical trials,5 a total of 4240 children 1 to 12 years of age received 1000-1625 PFU of attenuated virus
per dose of VARIVAX and have been followed for up to nine years post single-dose vaccination.
Vaccine Poulvac IB QX is based on a live attenuated virus